CVE-2026-66798

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

Not scored by EPSS

EPSS percentile

Not scored by EPSS

NVD base score

4.3 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

NVD analysis status

Received. NVD last modified this record on 2026-08-29.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-08-28 17:45Z12 HR AGO

Last updated

2026-08-29 03:56Z2 HR AGO

Reserved

2026-07-27

Assigning CNA

microsoft

Record state

PUBLISHED

Severity

Medium (CVSS 4.3)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C

Weaknesses

• CWE-416Use After FreeVariant

Data version

5.2

Document digest

d5a5283f1468e1ca77eabd1bacc68e9d8a339f91633bfe2dc8405208caa505df

• msrc.microsoft.comMicrosoft Edge (Chromium-based) Remote Code Execution Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66798vendor-advisorypatch